Posted
by
CmdrTaco
on Monday December 03, 2007 @11:23AM
from the begun-the-clone-wars-have dept.

damn_registrars writes "A fossilized hadrosaur has been uncovered in South Dakota that has preserved soft tissue. This is described as a "mummified" dinosaur, and allows for a look at the skin and musculature of some parts of this animal. The find was reported by a 24 year old Yale graduate student of paleontology."

According to the FTA, the find was originally located in 1999, and partially excavated in 2004 with a full investigation commencing in 2006. Having never studied archeology or paleontology, is it common for sites like this to be passed by even though there is something located there?

This isn't the first time they've gotten soft tissue from a dinosaur. A few years ago, they were trying to haul some dinosaur bones from a dig site by helocopter, but the bones wouldn't fit. After trying to solve the problem several ways, they made the agonized decision to break some of the largest bones. When they broke them open, they found soft tissue in one of them (I think it was a femur). A friend of mine (getting his phd in bioinfomatics) mentioned that they had managed to extract dinosaur proteins from this, and that because proteins are much more unstable then nucleic acids, it was entirely likely that they could extract dinosaur DNA from the specimen.

It's been several years since I've looked at any of the literature on the topic of ancient DNA, and my particular area of interest was the sequencing of human and Neandertal DNA in the arena of phylogenetics, but as I remember, the general consensus was that it would be extremely unlikely to be able to extract, amplify, and sequence enough DNA from specimens beyond, say, about 100,000 years old. The difficulties posed in specimens of geologic age would be even greater.

Apart from deterioration, contamination of specimens by modern DNA is a huge concern. I vaguely remember at least one instance where a published paper claimed to have sequenced DNA from fossilized leaves, when it later turned out that the specimen had been contaminated with modern plant matter, or something similar. Of course, when researching prehistoric human DNA, the chances of contamination are extremely high, are very difficult to detect. I'm not sure how difficult contamination would be to detect in animal samples, but I suspect it wouldn't be easy to rule out.

With the mosquitoes technique you'll find in the end several fragment of DNA per mosquitoe, with no way to know if they come from the same dino or if its contaminent from the mosquitoe.In the end you may have a very large library containing lots of sequence fragment. The building of this library would require a lot of money and time and won't have any direct benefit (= few would like to fund it).Then you would unleash bio informaticians to start mining the database, trying to sort the fragments and seeing which could fit which other.Only now could you get :- Comparison between the archeological fragment and modern sequence (Useful to understand how proteins evolved over time) ( - Warning, not fundie-compatible studies. May not get financed in conservative USA states)- Comparison of the fragments with already built phylogenetic modern trees (idem).

But given then "fragment" nature of the database on one hand and due to the repetition and sequence similarity inside a single genome on the other hand, you may not have enough information to sort a complete genome or even sort the fragments across severl species.That why the fictional Jurassic Park book used a lot of sequence of modern day species to help align the fragments and patch the holes.As a comparison there an actual experiment that picked up a lot of sample of sea water and sequenced whatever it managed to find inside. We end up with a lot of fragments but not much help to know wich sequence comes from what specie. This database is very hard to interpret. A dinosaur mosquitoe database would be similarily complex.

At least trying to find squences in fossilised soft tissue could make you believe that most of the few sequence you can manage to take out come from the same animal. But once again you'll get a lot of small sequence fragments that will be hard to put together.

According to an archeology professor of mine at Queen's University, this is very common. Excavation is a slow process, and one which is dependent on the weather. Furthermore, it is a funding intensive project.

You find a site, then you apply for funding. When you get your funding, you start the dig. Generally you only get the summer as rain, snow or ice can damage artifact and generally make digging harder. At the end of the digging season, you place some sort of modern marker at the edges and bottom of the trench (my professor used soda cans) and fill them in until the next time you can come back.

If your site proves to be interesting, you can get the funding renewed for another summer, and as a rule of thumb they give you funding every 2 years. This allows the funding to be spread out over a wider range of projects, and ensures the scientists have the time to publish what they found during the excavation.

1.) When cloning a sheep to give birth to itself, by putting a complete strand of its own DNA in its own egg cells in its own womb, we would have a one in several hundred chance of success. We don't know why, but the rest would be miscarriages, still births, or otherwise non-viable. The cloned animal would die early of old age, nobody knows why.

The problem with using "adult" DNA would be all the "junk" DNA that gets mixed in. Every time you get sick, a little bit of the bacteria or virii's DNA gets spliced into your own. Another issue is the timing of when certain genes are activated and deactivated in the initial construction phases (going from zygote to full embryo and then fetus). We know why the clones are dying, we just don't know how to stop it yet.

3.) DNA is relatively unstable. I doesn't survive completely intact for 65 million years no matter how you preserve it.

Correct. It's estimated human DNA can last roughly 250 years and remain relatively intact. Afterwards it begins to deteriorate. I'm unsure of whether the synthetic telomerase treatments that are in their research phases will affect it, but 250 years could be the cap of human life expectancy.

As a North Dakotan, I read about this find earlier today and was looking for a comment like yours to see if I had to write my own. I wish that our foreign enemies whose primary complaint is that Americans are ignorant of the rest of the world could understand that it's just a vocal minority (majority?... I'm not ready to be that cynical, just yet) of Americans who are ignorant of the entire world, including the most basic facts about their own nation.

For what it's worth, North Dakotans are as unaware that Virginia and the Carolinas are not the "East Coast," for instance, as the rest of the country is that North Dakota is a paleontologist's playground.

For those who aren't reading the article, you should, as it's a great story that everyone reading Slashdot dreamed about happening for himself all through his childhood. For those unwilling to read it, here's a capsule summary: A high school student in North Dakota found dinosaur bits in the Badlands and not much happened right away, but he was re-inspired to become a paleontologist. Now, as a Yale graduate student, he has come back to take another look, and a few years of digging later he has dug up the best specimen of a mummified dinosaur ever unearthed anywhere in the world.